Kensuke Kuraki, Kawasaki JP

Kensuke Kuraki, Kawasaki JP

Patent application number

Description

Published

20080205699

DIGITAL WATERMARK EMBEDDING AND DETECTION - Provided is a digital watermarking technology for embedding digital watermark information in text data thereby to generate a digitally watermarked image. The technology includes a digital watermarking program, a digital watermarking device and a digital watermarking method, in which digital watermark information can be embedded in document in such a way as not to be easily detected visually and be stably detected even after being printed out, copied or scanned by detecting the features of a character as data to be digitally watermarked, such as the direction and thickness of a line composing the character as the features thereof and embedding the digital watermark information in the character on the basis of the detected features.

DIGITAL WATERMARK EMBEDDING APPARATUS AND DIGITAL WATERMARK DETECTING APPARATUS - A plurality of background texture patterns each of which includes a region not having a dot and having a feature different from those of the other background texture patterns, are combined, and information is embedded in a background region of a document image. Then, a mathematical-morphology-based conversion is performed on the document image, and thereby a feature of a region not having a dot in each of the background texture patterns is extracted in order to identify the embedded information.

07-09-2009

20090214033

IMAGE ENCRYPTION APPARATUS AND IMAGE DECRYPTION APPARATUS - Area data indicating an encryption area of image data and level data indicating an authority level for the encryption area are received. Upon being triggered by an input password, an encryption key is generated for each received authority level. Check data to be detected in verifying whether or not the encrypted image data in the encryption area is appropriately decrypted through decryption is implanted in the encryption area. Image encryption is performed on the encryption area where the check data is implanted, by using the encryption key corresponding to the authority level designated for the encryption area. In decryption, all decryption keys corresponding to all authority levels lower than or equal to the set authority level are used to decrypt each encryption area and determines whether or not an appropriate decryption has been performed on the basis of the result of the detection of the check data.

08-27-2009

20090220076

Image decrypting apparatus, image encrypting apparatus, and image decrypting method - When a decrypting apparatus receives an encrypted image, the apparatus detects the state of the encrypted image and determines whether the encrypted image is an image passed through only a digital medium or an analog medium, according to the state of the encrypted image. When the encrypted image is determined to be the image passed through only the digital medium, the decrypting apparatus switches to perform a digital decryption process and, when the encrypted image is determined to be the image passed through the analog medium, the decrypting apparatus switches to perform an analog decryption process.

09-03-2009

20090238361

IMAGE ENCRYPTION APPARATUS AND IMAGE DECRYPTION APPARATUS - In an image encryption apparatus, an input processor inputs data of an input image. An encryptor encrypts a part or whole of the data of the input image. A marker generator generates data of a marker indicating an encrypted area. An image saver saves data of a marker-covered image covered with the marker. A marker sticker sticks the marker. An output processor outputs an encrypted image. In an image decryption apparatus, an input processor inputs data of an input image. A marker detector detects a marker and identifies an encrypted area. A decryptor decrypts data in the encrypted area. An image restorer restores data in an area covered with the marker by sticking data of a marker-covered image. An output processor outputs data of a decrypted image.

09-24-2009

20090245511

IMAGE ENCRYPTION APPARATUS AND IMAGE DECRYPTION APPARATUS - In an image encryption apparatus, each of pixel-value inverse-converters applies pixel-value inverse-conversion on an input image in each of previously-encrypted areas. An image combiner superimposes images with inversely-converted pixels in the previously-encrypted areas to the input image to obtain a ready-to-encrypt image. An image encryptor scrambles blocks in the ready-to-encrypt image. A pixel-value converter applies pixel-value conversion on each of scrambled blocks to obtain a multiply-encrypted image. In an image decryption apparatus, a pixel-value inverse-converter applies pixel-value inverse-conversion on each scrambled block in the multiply-encrypted image to obtain a dot-erased image. An image decryptor inversely scrambles the scrambled blocks in the dot-erased image to obtain a decrypted image. Each of pixel-value converters applies pixel-value conversion on the decrypted image in each of previously-encrypted areas. An image combiner superimposes images with converted pixels in the previously-encrypted areas to the decrypted image to obtain a previously-encrypted image.

10-01-2009

20090245512

IMAGE DECRYPTION APPARATUS - A display processor displays on a display screen an encrypted image accepted by an image data acceptor. An encrypted region acquirer extracts encrypted regions contained on the encrypted image. A target region selector or an authorized target region selector selects decryption target regions from among encrypted regions contained in the encrypted image. A decryption order determiner determines a decryption order of the decryption target regions. The display processor displays on the display screen a prompt for inputting a decryption key (or a password) used for decryption of the encrypted image in each of the decryption target regions in accordance with the decryption order. A decryption key acceptor accepts the decryption key input by a decryption user. An image decryptor performs a decryption process on the encrypted image in the decryption target regions in accordance with the decryption order. A decrypted image of each decryption target region is output.

10-01-2009

20090245513

IMAGE ENCRYPTION APPARATUS AND IMAGE DECRYPTION APPARATUS - In an image encryption apparatus for visually encrypting an input image, an encryption area selector selects an encryption area within an input image including an area to be encrypted. An image converter divides the encryption area into a plurality of blocks. The image converter divides each block of the encryption area into a plurality of sub-blocks. An image converter performs an image conversion including rotation and mirror-reverse in accordance with an encryption key on the image in each sub-block. The image converter scrambles the image on a block-by-block basis in accordance with the encryption key. A pixel value converter converts a pixel value of a minimal area in a block so that a position of the block may be detected.

10-01-2009

20090257586

Image processing apparatus and image processing method - An image processing apparatus sections an image to be processed into a plurality of blocks, rearranges the blocks into positions specified by an encryption key that uniquely specifies the positions of the blocks in the image, determines a computing method used to convert pixel values of pixels that form a minimum area included in each of the blocks after the blocks are rearranged based on the pixel values of predetermined pixels that do not belong to the minimum area, and converts the pixel values based on the computing method.

10-15-2009

20090262931

DEVICE, METHOD, AND PROGRAM FOR IMAGE ENCRYPTION/DECRYPTION - In order to encrypt a part of an input image in such a manner that the encrypted part can be located for decryption, means for regularly converting pixel values in the area to be encrypted and generating a pattern unique to the pixel value conversion in order to encrypt the area to be encrypted; means for setting a specified positioning marker for locating an encryption position at two or more of the four corners of the area to be encrypted; and means for setting one or more checking marks for verifying appropriateness of a decrypted image in the encrypted area before the decryption are included.

10-22-2009

20090323950

Image encryption/decryption apparatus, method and program - An image encryption apparatus encrypts a digital image by specifying a partial region from the digital image, converting the selected partial region into a processing image based on an encryption key, and specifying a position of the partial region by regularly converting a pixel value of the processing image.

12-31-2009

20100042828

DOCUMENT DATA ENCRYPTION METHOD AND DOCUMENT DATA ENCRYPTION SYSTEM - An encrypting device encrypts original document data by use of a password of an addressee, thereby generating encrypted document data. A decryption authority changing device, of which operating authority is held by the addressee, generates authority changing information M structured by encrypting the password of the addressee with a password of a proxy, and notifies a decrypting device of the information, of which the operating authority is held by the proxy. The decrypting device decrypts the password of the addressee by employing the password of the proxy, and decrypts the encrypted document data by use of the decrypted password of the addressee.

02-18-2010

20100067706

IMAGE ENCRYPTING DEVICE, IMAGE DECRYPTING DEVICE AND METHOD - An encrypting device generates an encrypted image by converting an image of a specified region in an input image with an encryption key, by embedding information obtained by encrypting the encryption key with a public key pairing with the private key of a destination, and by performing pixel value conversion. Then, the encrypted image is transmitted to the destination as a printed matter or via a network. A decrypting device converts the encrypted image in the form of print data or electronic data into an image, and inputs it. Next, the decrypting device extracts a decryption key (the encryption key) from the image of the encryption region by executing a process reverse to that of the encrypting device for the encryption region of the converted encrypted image. Then, the decrypting device decrypts the original image of the encrypted region by using the decryption key, and restores the entire encrypted image.

03-18-2010

20100074443

IMAGE ENCRYPTION AND IMAGE DECRYPTION APPARATUS AND METHOD - Input data is converted into an image, and in the input image, an encryption region that is a region in which the image is to be encrypted. Meanwhile, on the basis of an encryption key, encryption key-related information that is information related to the encryption key is generated, and the encryption key-related information is embedded into the image in the encryption region, to generate a first intermediate image. Next, the first intermediate image is converted on the basis of the encryption key, to generate a second intermediate image. Then, the pixel values of the second intermediate image are converted so that the position of the encryption region can be specified. As a result of the conversion, an encrypted image in which the part corresponding to the encryption region in the input image is generated.

03-25-2010

20100158311

Electronic watermark embedding device, electronic watermark detecting device, and programs therefor - An electronic watermark embedding device that embeds a graphic pattern representing information in image data includes a signaling feature period changing unit configured to change a period of signaling feature of a graphic pattern, a graphic pattern embedding unit configured to embed the graphic pattern in the image data as a period of the signaling feature changed by the signaling feature period changing unit, and an embedment region detecting unit configured to detect an embedding position where the graphic pattern is embedded from a region of the image data other than a background, whereby the signaling feature period changing unit changes the period of the signaling feature while maintaining the signaling feature when the image data undergo image enlargement or reduction processing, and the graphic pattern embedding unit embeds the graphic pattern in the embedding position on the region of the image data other than the background.

06-24-2010

20100158383

IMAGE MARKER ATTACHING APPARATUS AND METHOD - A marker attaching apparatus attaches to an image a positioning marker for detecting a specific area in the image, and includes: an area size detection unit detecting a size of an area to which the positioning marker is attached; a marker adjustment unit adjusting the positioning marker depending on the detected size of the area; and a marker attaching unit attaching the adjusted positioning marker to the image.

MARKER PLACEMENT DEVICE, MARKER PLACEMENT DETECTING DEVICE, AND COMPUTER READABLE STORAGE MEDIUM FOR STORING MARKER PLACEMENT PROGRAM - A marker placement device includes, a marker placement method decision section that decides, for every predetermined pitch from a starting edge of a side to an end edge of the side, a placement position of a marker for detecting a position within a rectangular image region, the placement position being along the side of the image region within an image. A marker adding section that adds the marker to the image according to the placement position decided is provided, where, when a gap shorter than the pitch remains between the end edge and the decided placement position closest to the end edge of the side, the marker placement method decision section decides a first marker placement position closest to the starting edge, and decides a subsequent marker placement position.

09-22-2011

20110229043

IMAGE PROCESSING APPARATUS AND IMAGE PROCESSING METHOD - An image processing apparatus includes: an interface unit for acquiring a readout image produced by capturing an image formed on a medium; a storage unit for storing a plurality of templates generated by superimposing different amounts of blurring on a prescribed pattern contained in the image, and for storing the amounts of blurring superimposed on the respective templates; and a processing unit adapted to detect a pattern region where the prescribed pattern is located on the readout image, calculate the degree of matching between the pattern region and each of the plurality of templates and, based on the degree of matching, identify a template that most closely matches the prescribed pattern located on the readout image, and estimate that the amount of blurring corresponding to the most closely matching template represents the amount of blurring superimposed on the readout image.

09-22-2011

20110249300

IMAGE PROCESSING SYSTEM, IMAGE PROCESSING APPARATUS, AND IMAGE PROCESSING METHOD - An image processing system includes: an image input unit which reads an image printed on a medium and generates electronic data representing the image; and a processing unit which corrects the image represented by the electronic data. The processing unit implements the functions of: detecting, from the image represented by the electronic data, a first pattern having a first size and shape that is attached to the image; measuring a degree of degradation by measuring an amount of displacement of the size of the detected first pattern from the first size; and correcting the image represented by the electronic data to reduce the degree of degradation.

10-13-2011

20110280395

IMAGE ENCRYPTION DEVICE, IMAGE DECRYPTION DEVICE AND METHODS - Constraints are added to the size of an encryption area at the time of encryption processing. For example, if the respective number of horizontal and vertical divided blocks is divided by a predetermined positive integer, the size of the encryption area is limited such that the remaining is a certain number of 0 (namely, a multiple of the predetermined positive integer to the respective number of blocks) or 1 or more. Block positions in the encryption area are detected according to the constraints of the number of blocks of an encryption image as the decryption processing corresponding to the encryption processing. Because the number of horizontal and vertical blocks is previously limited at the time of the encryption, the possibility of the number of blocks to be considered in the detection of the block positions is reduced, resulting in improved decryption accuracy.

11-17-2011

20110317935

IMAGE PROCESSING DEVICE, METHOD THEREOF, AND A COMPUTER READABLE NON TRANSITORY STORAGE MEDIUM STORING AN IMAGE PROCESSING PROGRAM - An image processing device includes, a block division unit configured to divide at least a part of an area of an input image into a plurality of blocks; a block classification unit configured to classify each block in the input image into a white block and a black block based on a variance of luminance values in a white block that typically includes white pixels and a variance of luminance values in a black block that includes at least black pixels among white pixels and black pixels; and a luminance correction unit configured to correct a luminance value of each pixel in a black block in the input image based on an average luminance value of pixels in one or more white blocks in the vicinity of the black block.

12-29-2011

20120002877

Non-transitory computer readable storage medium, marker creating apparatus, restoration apparatus, and marker creating method - When creating a marker, an encryption apparatus extracts each pixel value in a region and allows a storing unit to save, as restoration information, the high-order bits of each extracted pixel value. Then, the encryption apparatus creates a marker by changing the high-order bits of the pixel value in a region in which the marker is created and embeds encrypted information in an encrypted region specified by the marker. When decoding the encrypted information, a decoding apparatus detects the marker from a digital image, decodes the encrypted information in the encrypted region specified by the marker, and overwrites bits contained in the restoration information with the high-order bits of the pixel value of the marker.

01-05-2012

20120121086

IMAGE ENCRYPTION/DESCRYPTION DEVICE, METHOD, AND STORAGE MEDIUM STORING A PROGRAM - At the time of marker attachment (at the time of encryption), for example, image conversion in which pixels to be overwritten by a marker are selected and pruned in a distributed manner and the pruning positions are moved to a marker attachment position is performed, and the marker is attached to the marker attachment position obtained as a result. At the time of marker elimination (at the time of decryption), for example, image reverse conversion in which each pixel of the marker is moved to the original position before the marker attachment is performed, each moved pixel of the marker is recovered, and the marker is eliminated.

05-17-2012

20120163583

DIGITAL WATERMARK EMBEDDING DEVICE, COMPUTER-READABLE RECORDING MEDIUM, AND DIGITAL WATERMARK DETECTING DEVICE AND COMPUTER-READABLE RECORDING MEDIUM - An digital watermark embedding device including an interface unit configured to acquire content in a digital form and digital watermark information, the device includes, a codeword generating unit configured to generate a base codeword including a bit sequence including the digital watermark information; a shifting unit configured to generate a plurality of correcting codewords differing from one another by permutating an arrangement in the bit sequence included in the base codeword depending on a plurality of shift amounts, the plurality of shift amounts differing from one digital watermark information to another, under a predetermined permutation rule; and a watermark superimposing unit configured to embed the plurality of correcting codewords in the content.

06-28-2012

20120163653

DIGITAL WATERMARK EMBEDDING APPARATUS, DIGITAL WATERMARK EMBEDDING METHOD, AND DIGITAL WATERMARK DETECTION APPARATUS - A digital watermark embedding apparatus includes an interface unit which acquires video data and digital watermark information, and a processing unit which embeds the digital watermark information into the video data. The processing unit is adapted to cause the area of a watermark pattern formed by a plurality of pixels having a prescribed value, and superimposed on each image contained in the video data, to vary in periodic fashion over time according to the value of a symbol contained in the digital watermark information, and correct, using the prescribed value, the value of each pixel contained in a region where each image in the video data and the watermark pattern corresponding to that image overlap each other.